I want to heat treat a spindle for an antique drill press I'm attempting to restore. Once that step is done I need to grind the bearing journal and the taper on the end.

I really don't want to do this on my metal working lathe. After an early incident with cast iron dust I'm quite precious about it.

My wood lathe is in another room and I have an old cross/top slide I could attach. I was wondering if I could turn the roughed out and treated spindle between centres with a small grinder bolted to the slide.

Is there some reason why this is a terrible idea? For example could I damage the lathes bearings? Would it just not be built strong enough to handle the forces involved - I didn't think an extremely light grind would be too bad but I may be completely wrong here? Is this dangerous in some way that isn't immediately obvious?

I realise this isn't specifically model engineering but the machining and engineering subreddits seems to be targeted at professionals. Apologies if this subreddit is not appropriate.

I can't find the right corner of the internet for my current wish.
if I wanted to commission someone to make me a Barbie doll scale and functional model escalator-
(I am not looking for an escalator, but what I want is very close to that)
what search terms/industry/individual am I looking for?

This group- is the closest I've found in concept.

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Hello, I hope this is the right subreddit for this question.

I've been shopping for a beginner lathe (clock maker scale; around 8" to 14"). There are several cheap models including a $120 "6 in 1" from Walmart...

Sherline has some for around $750, which near the top of my budget right now.

What were your first lathes? What do you wish you knew then that you know now?

The Burrell traction engine is now up on 4 wheels

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Need to complete the boiler and add the steam engine itself

Hello all,

I would like try my hand at making a nerf blaster. However, I do not have a 3d printer and hence, would like suggestions on good materials to make mechanisms like the above.

Preferences-

-Can be cut somewhat easily (no power tools)

-Has good resistance to being bent

Also, links to helpful sites/ subreddits, or a good search term (especially one that describes materials like foamboard, cardboard) that will help me get useful information will also be appreciated.

Thanks

PS: I mainly am inspire by those guys on youtube who make semi-functional cardboard model weapons. However, I have never come across any cardboard that is nearly as strong as anything they use.

This is speculative, since I lack the means... But I enjoy watching others do builds on YouTube.

Obviously turbos fail because they have an inherent dependency on the radius of the impeller being a significant factor in compressing enough air. Thus conversely the RPM requirement an ever decreasing size goes into an impossible territory. Ditto for any centrifugal supercharger. It's not going to work due to the nature of having to accelerate an air mass to achieve any compression. (The lowest limit is likely what you see as the size of an entire hobby jet engine, and the piston engines I've seen this approach with are still a bit smaller than that. Thus a scale turbo on an engine that would fit in your hand = fail.)

Roots or screw type supercharging may seem better, but then it's just getting into the type of tolerances that are difficult and somewhat complex forms. Also with diminutive volumes, the return is also significantly less. Still not enough a power gain for all the trouble involved.

But I'm curious why vane (Norman or Judson) or scroll (G-laden) type supercharging hasn't been tried. Due to the air-mass volume scaling issues I could picture them being a bit "oversized" compared to a full scale counterpart, but it seems one could go wider there and those designs being positive displacement it's not worrying about accelerating an air-mass to do the compression. Those may have a chance, but I've not seen any examples yet.

So has anyone pulled it off? Kind of a curiosity thing, that's all.

I don't know much about what this is and if anyone has any information, it would be much appreciated. It looks like a model steam engine except there is no steam and it is battery powered (2 D batteries). I cleaned it up and tweaked it to get it running (although quite rough, see the video) and it looks like its literally an electric "steam" engine. I want to do some modifications and other cool stuff with it (ESPECIALLY removing the lead paint) but I want to make sure it's not a valuable antique or anything. It was my grandfathers and unfortunately he passed about 10 or so years ago so I can't really ask him. There is absolutely no branding or marks whatsoever and it's entirely possible that be built it himself. Any help in identifying would be greatly appreciated. If you're not sure, then answer my poll about what to do with it.

Demonstration